(1) Field of the Invention
The present invention relates to a thin film transistor array panel and a manufacturing method thereof.
(2) Description of the Related Art
A thin film transistor (“TFT”) array panel is often used as a circuit board to drive pixels in a display device such as a liquid crystal display (“LCD”) or an organic light emitting device (“OLED”), for example.
The thin film transistor array panel typically includes a gate line for transmitting a gate signal, a data line for transmitting a data signal, a thin film transistor connected to the gate line and the data line and a pixel electrode connected to the thin film transistor.
More particularly, the thin film transistor includes a gate electrode connected to the gate line, a semiconductor layer forming a channel, a source electrode connected to the data line and a drain electrode facing the source electrode with the semiconductor layer disposed therebetween. Thus, the thin film transistor is a switching element for controlling the data signal transmitted to the pixel electrode via the data line according to the gate signal supplied to the thin film transistor via the gate line.
Typically, the pixel electrode is connected to the drain electrode through a contact hole formed in a passivation layer, to thereby receive the data signal.
However, an aperture ratio of the pixel is decreased as a size of the contact hole is increased. Additionally, a slope of a side wall of the contact hole becomes steeper as the size of the contact hole is decreased and, as a result, a defect occurs, such as the pixel electrode becoming disconnected.